Where does “אֲנָא” come from?

אֲנָא (Aramaic) comes from Proto-Semitic ʔanāku, from Proto-Afro-Asiatic ˀanāku.

Ancestry of “אֲנָא”, step by step

Step	Language	Word	Meaning
1	Proto-Semitic	ʔanāku	I
2	Proto-Afro-Asiatic	ˀanāku	—